Safety steam-gage fob steam-boilers



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UNITED sTATEs PATENT oEEIoE.

JOHN A. ROEBLING, OF SAXONBURG, PENNSYLVANIA.

i p SAFETY STEAM-GAGE FOR STEAM-BOILERS.

Specification of Letters Patent No. 2,728, dated July 16, 1842.

T0 all whom it may concern: i

Be it known that I, JOHN AUGUSTUS ROEBLING, of Saxonburg, in thecountyof Butler, State of Pennsylvania, have invented a new andIinprovedSelf-Acting Safety- Gage for SteamfBoilers; and I do hereby declare thatthe following is a full and exact description.

The principle of my invention consists in the application of a commonconical steam gage such as is generally used on the high pressureboilers of the Vest, in one of the boiler heads; the stem of the valvebeing extended inside of the boiler several inches, and furnished with ahead, against which the vertical and short arm of a lever will act,whose other and longer arm is supplied with a weight which may be of theshape of a hammer, this weight being supported upon the surface offusible metal, which is in closed in a bo-X, which is placed upon thetop of one of the flues, so that when the level of the water sinks belowthe fusible metal the rapid absorption of heat from the flue willspeedily melt the alloy, which then no longer affords a support to thehammer. The pressure of the short lever against the valve stem whichresults from the weight attached to the long lever, will now readilyopen -the gage and allow steam to escape, which by its hissing` noisewill warn the engineer of the approaching danger.

The hammer or weight should be raised again to its former position byclosing the valve, before the deficiency of water is supplied, so thatthe surface of the alloy may resume itsformer level, while in a state offusion. But in order to assist the rise of the hammer, another gage isarranged below the first, the stem of which, when pressed, will act uponthelower arm of the lever, and must be kept in that position, until theboiler is supplied and the alloy cooled. lVhere there is no room for thelower gage, it may be placed sideways, and the lower lever arm be bentto suit its position. i

To prevent the settling of dirt and sediment from the boiler water uponthe surface of the alloy, the box, containing it, may` be covered, butso as to leave the hammer and lever at liberty to rise and `fall andallow the water inside to communicate with that The accompanying drawingwill explain the construction of the apparatus,

Figure l shows the longitudinal section,

and Fig. 2 the cro-ss section taken through i `pressed by the stem L ofthe lower gage,

will raise the hammer. i

7e Z shows the top of the flue.

In the `second diagram m represents a cross section of the Hue, to whichthe apparatus is attached.

Diagram 3 shows a cross section on a smaller scale of a boiler with twoflues and an alloy box attached to one of them.

I propose that the gage cocks with which the apparatus is connected,should be used as common gages for the purpose of ascertaining the stageof the water at all times. Being thus constantly used, theyT can neverbecome fixed in their seats and will always be in a condition to beacted on by the lever.'

be in the shape of a hammer, the head of which rests on the surface offusible metal,

which is contained in a box and secured Aupon the top of a flue, so thatwhen the water inthe boiler sinks too low and exposes the alloy, thiswill readily melt from the heat of the flue and allow the hammer tosink, which then by its leverage will open a gage and give alarm `by theescape of steam. I do not claim the principle o-f applying fusiblealloy,'but only the application of a lever in shape of a hammer or anyother convenient shape in connection with a gage or gages to be actedupon by the melting of' an alloy, the apparatus being arranged andoperating substantially in the manner fully explained and describedabove.

JOHN A. ROEBLING.

` Witnesses:

AARON B. DAVIS, J oHN DAVIS.

